diff --git a/buildbot/master.cfg b/buildbot/master.cfg
index 4638db5d..ff8288eb 100644
--- a/buildbot/master.cfg
+++ b/buildbot/master.cfg
@@ -108,9 +108,11 @@ c['schedulers'].append( SingleBranchScheduler(
                                           "build-osx-py36",
                                           "build-osx-py37",
                                           "build-gtk-py27",
-                                          "build-gtk-py35",
+                                          "build-gtk-py36",
+                                          "build-gtk-py37",
                                           "build-gtk3-py27",
-                                          "build-gtk3-py35",
+                                          "build-gtk3-py36",
+                                          "build-gtk3-py37",
                                           ]))
 
 
@@ -173,9 +175,11 @@ c['schedulers'].append( ForceScheduler(
                                           "build-osx-py36",
                                           "build-osx-py37",
                                           "build-gtk-py27",
-                                          "build-gtk-py35",
+                                          "build-gtk-py36",
+                                          "build-gtk-py37",
                                           "build-gtk3-py27",
-                                          "build-gtk3-py35",
+                                          "build-gtk3-py36",
+                                          "build-gtk3-py37",
                                           "dist-osx-py27",
                                           "dist-osx-py34",
                                           "dist-osx-py35",
@@ -227,23 +231,30 @@ from buildbot.config import BuilderConfig
 def makeFactory(port, buildType='buildOnly', pyVer='2.7'):
     factory = BuildFactory()
 
-    # Was the build started from the force build form with a "fullclean"
-    # property set? If so, fully clobber the git workspace and start fresh.
-    cmd = ['bash', '-c',
-           WithProperties('if [ %(fullclean:-no)s == yes ]; then rm -rf ../Phoenix; echo fully cleaned; fi'),
-           ]
-    factory.addStep(ShellCommand(command=cmd, description='fullclean?', workdir=""))
+    if False:
+        # Was the build started from the force build form with a "fullclean"
+        # property set? If so, fully clobber the git workspace and start fresh.
+        cmd = ['bash', '-c',
+            WithProperties('if [ %(fullclean:-no)s == yes ]; then rm -rf ../Phoenix; echo fully cleaned; fi'),
+            ]
+        factory.addStep(ShellCommand(command=cmd, description='fullclean?', workdir=""))
 
 
-    # By default do an incremental update, keeping prior build tree
-    mode = 'incremental'
-    method = None
-    clean = ''
+        # By default do an incremental update, keeping prior build tree
+        mode = 'incremental'
+        method = None
+        clean = ''
 
-    # Start from a clean build tree for the daily "dist" builds
-    if buildType in ['dist', 'sdist', 'docs', 'vagrant']:
+        # Start from a clean build tree for the daily "dist" builds
+        if buildType in ['dist', 'sdist', 'docs', 'vagrant']:
+            mode = 'full'
+            method = 'clobber'
+
+    else:
+        # Always do a clean build.
         mode = 'full'
         method = 'clobber'
+        clean = ''
 
     # extra config options for git commands
     gitConfig = {'core.autocrlf' : 'input'}
@@ -361,17 +372,25 @@ c['builders'] = [
                       slavenames=["ubuntu-x64_86-py27"],
                       factory=makeFactory('gtk2')),
 
-        BuilderConfig(name="build-gtk-py35",
+        BuilderConfig(name="build-gtk-py36",
                       slavenames=["ubuntu-x64_86-py27"],
-                      factory=makeFactory('gtk2', pyVer='3.5')),
+                      factory=makeFactory('gtk2', pyVer='3.6')),
+
+        BuilderConfig(name="build-gtk-py37",
+                      slavenames=["ubuntu-x64_86-py27"],
+                      factory=makeFactory('gtk2', pyVer='3.7')),
 
         BuilderConfig(name="build-gtk3-py27",
                       slavenames=["ubuntu-x64_86-py27"],
                       factory=makeFactory('gtk3')),
 
-        BuilderConfig(name="build-gtk3-py35",
+        BuilderConfig(name="build-gtk3-py36",
                       slavenames=["ubuntu-x64_86-py27"],
-                      factory=makeFactory('gtk3', pyVer='3.5')),
+                      factory=makeFactory('gtk3', pyVer='3.6')),
+
+        BuilderConfig(name="build-gtk3-py37",
+                      slavenames=["ubuntu-x64_86-py27"],
+                      factory=makeFactory('gtk3', pyVer='3.7')),
 
 
         BuilderConfig(name="dist-docs",